Abstract 111: NEDD8 Ultimate Buster-1 Long (NUB1L) Protein Regulates Atypical Neddylation and Protects Against Myocardial Ischemia-reperfusion Injury

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Jie Li ◽  
Wenxia Ma ◽  
Huizhong Li ◽  
Ning Hou ◽  
Xuejun Wang ◽  
...  

Neddylation is a ubiquitination-like pathway that covalently conjugates NEDD8 to target proteins and involves in diverse cellular processes. Under stress conditions, NEDD8 forms a chain or mixes with ubiquitin to modify protein substrates in NEDD8 conjugating enzymes-independent manner (atypical neddylation). The functional consequence of atypical neddylation remains unexplored in any cell types including cardiomyocytes. Here we report that increased neddylated proteins were observed in desmin-related cardiomyopathic (DRC) mouse hearts, mouse hearts subjected to myocardial ischemia-reperfusion (I/R) and human failing hearts. In cultured cardiomyocytes, multiple cellular stresses induced atypical neddylation, which was attenuated by NUB1L overexpression but exaggerated by loss of NUB1L, revealing NUB1L as a negative regulator of atypical neddylation. Activation of atypical neddylation by forced expression of NEDD8 accumulated a proteasome surrogate substrate GFPu, while suppression of atypical neddylation by NUB1L overexpression enhanced the degradation of GFPu and a DRC-linking misfolded protein. NUB1L is necessary and sufficient to protect cardiomyocytes against proteotoxic stress-induced cell injury. In vivo, cardiac-specific overexpression of NUB1L (NUB1L-O/E) in mice dose-dependently reduced neddylated proteins and facilitated the degradation of the proteasome surrogate substrate. NUB1L-O/E mice displayed no discernible cardiac structural and functional abnormality at baseline, but exihibted reduced apoptotic cardiomyocytes, limited infarct sizes and preserved cardiac function in response to I/R. We therefore conclude that NUB1L suppresses atypical neddylation, enhances proteasome proteolytic function and protects against myocardial I/R injury. Targeting atypical neddylation could be a novel therapeutic strategy to treat cardiac ischemic cardiomyopathy.

2021 ◽  
Vol 8 ◽  
Author(s):  
Gecai Chen ◽  
Aihuan Yue ◽  
Meixiang Wang ◽  
Zhongbao Ruan ◽  
Li Zhu

The purpose of the study was to explore the mechanism by which myocardial ischemia-reperfusion (I/R) injury-induced exosomes modulate mesenchymal stem cells (MSCs) to regulate myocardial injury. In this study, we established an I/R injury model in vivo and a hypoxia-reoxygenation (H/R) model in vitro. Then, exosomes isolated from H/R-exposed H9c2 cells were characterized using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot analysis. CCK-8 assays and flow cytometry were performed to assess cell injury. ELISA was applied to determine the level of insulin-like growth factor 1 (IGF-1). Echocardiography was used to assess cardiac function in vivo. HE staining and TUNEL assays were conducted to analyze myocardial injury in vivo. In the present study, H/R-exposed H9c2 cells induced IGF-1 secretion from MSCs to inhibit cell myocardial injury. Moreover, exosomes derived from H/R-exposed H9c2 cells were introduced to MSCs to increase IGF-1 levels. The lncRNA KLF3-AS1 was dramatically upregulated in exosomes derived from H/R-treated H9c2 cells. Functional experiments showed that the exosomal lncRNA KLF3-AS1 promoted IGF-1 secretion from MSCs and increased H9c2 cell viability. In addition, miR-23c contains potential binding sites for both KLF3-AS1 and STAT5B, and miR-23c directly bound to the 3'-UTRs of KLF3-AS1 and STAT5B. Furthermore, the lncRNA KLF3-AS1 promoted IGF-1 secretion from MSCs and rescued myocardial cell injury in vivo and in vitro by upregulating STAT5B expression. The lncRNA KLF3-AS1 may serve as a new direction for the treatment of myocardial I/R injury.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Chelsea Organ ◽  
Zhen Li ◽  
Yu Zhao ◽  
Chuntao Yang ◽  
Shashi Bhushan ◽  
...  

Background: Hydrogen sulfide (H2S) protects against acute myocardial ischemia/reperfusion (MI/R) injury and heart failure by ameliorating oxidative stress, improving mitochondrial function, and attenuating apoptosis. One of the major limitations of currently available H2S donors is poor pharmacokinetics profiles that result in very rapid and uncontrolled H2S release. NSHD-1 and NSHD-2 are recently developed thiol-activated H2S donors designed for sustained release of H2S upon activation by molecules containing thiol groups such as cysteine and glutathione. We hypothesized that these novel H2S donors would generate H2S for extended periods and ameliorate myocardial cell death following MI/R in an in vivo murine model. Methods and Results: C57BL6/J male mice (10-12 weeks of age) were subjected to 45 minutes of MI followed by 24 hours of R. At the time of reperfusion, animals received Vehicle (0.5% THF), NSHD-1 (50 μg/kg and 100 μg/kg), or NSHD-2 (50 μg/kg) by direct intracardiac (i.c.) injection. In addition, at 4 hours of R, plasma was collected for troponin-I measurements. In preliminary studies we observed sustained release of H2S with both of these H2S donors. Myocardial infarct size was reduced by 35% (p < 0.01 vs. Vehicle) in mice treated with NSHD-1 (100 μg/kg), 43% (p < 0.05 vs. Vehicle) in mice treated with NSHD-2 (50 μg/kg), and 54% (p < 0.01 vs. Vehicle) in mice treated with NSHD-2 (100 μg/kg). Conclusions: NSHD-1 and NSHD-2 significantly attenuate MI/R injury in a murine model. Experiments are currently underway to further define the in vivo pharmacokinetics of H2S release from these agents, mechanisms of action, and safety profile.


2008 ◽  
Vol 295 (5) ◽  
pp. H2128-H2134 ◽  
Author(s):  
Atsuko Motoki ◽  
Matthias J. Merkel ◽  
William H. Packwood ◽  
Zhiping Cao ◽  
Lijuan Liu ◽  
...  

Soluble epoxide hydrolase (sEH) metabolizes epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids. EETs are formed from arachidonic acid during myocardial ischemia and play a protective role against ischemic cell death. Deletion of sEH has been shown to be protective against myocardial ischemia in the isolated heart preparation. We tested the hypothesis that sEH inactivation by targeted gene deletion or pharmacological inhibition reduces infarct size (I) after regional myocardial ischemia-reperfusion injury in vivo. Male C57BL\6J wild-type or sEH knockout mice were subjected to 40 min of left coronary artery (LCA) occlusion and 2 h of reperfusion. Wild-type mice were injected intraperitoneally with 12-(3-adamantan-1-yl-ureido)-dodecanoic acid butyl ester (AUDA-BE), a sEH inhibitor, 30 min before LCA occlusion or during ischemia 10 min before reperfusion. 14,15-EET, the main substrate for sEH, was administered intravenously 15 min before LCA occlusion or during ischemia 5 min before reperfusion. The EET antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (EEZE) was given intravenously 15 min before reperfusion. Area at risk (AAR) and I were assessed using fluorescent microspheres and triphenyltetrazolium chloride, and I was expressed as I/AAR. I was significantly reduced in animals treated with AUDA-BE or 14,15-EET, independent of the time of administration. The cardioprotective effect of AUDA-BE was abolished by the EET antagonist 14,15-EEZE. Immunohistochemistry revealed abundant sEH protein expression in left ventricular tissue. Strategies to increase 14,15-EET, including sEH inactivation, may represent a novel therapeutic approach for cardioprotection against myocardial ischemia-reperfusion injury.


2016 ◽  
Vol 94 (12) ◽  
pp. 1267-1275 ◽  
Author(s):  
Yidan Wei ◽  
Meijuan Xu ◽  
Yi Ren ◽  
Guo Lu ◽  
Yangmei Xu ◽  
...  

Arachidonic acid (AA) is a precursor that is metabolized by several enzymes to many biological eicosanoids. Accumulating data indicate that the ω-hydroxylation metabolite of AA, 20-hydroxyeicosatetraenoic acid (20-HETE), is considered to be involved in the myocardial ischemia–reperfusion injury (MIRI). The inhibitors of AA ω-hydroxylase, however, are demonstrated to exhibit protective effects on MIRI. Dihydrotanshinone I (DI), a bioactive constituent of danshen, is proven to be a potent inhibitor of AA ω-hydroxylase by our preliminary study in vitro. The purpose of the present study was to investigate the cardioprotection of DI against MIRI and its effects on the concentrations of 20-HETE in vivo. Rats subjected to 30 min of ischemia followed by 24 h of reperfusion were assigned to intravenously receive vehicle (sham and ischemia–reperfusion), low (1 mg/kg), middle (2 mg/kg), or high (4 mg/kg) doses of DI before reperfusion. The results demonstrated that DI treatment could improve cardiac function, reduce infarct size, ameliorate the variations in myocardial zymogram and histopathological disorders, decrease 20-HETE generation, and regulate apoptosis-related protein in myocardial ischemia–reperfusion rats. These findings suggested DI could exert considerable cardioprotective action on MIRI by the attenuation of 20-HETE generation, subsequent myocardial injury, and apoptosis through inhibition on AA ω-hydroxylase.


2013 ◽  
Vol 464 ◽  
pp. 37-40
Author(s):  
Da Peng Gao ◽  
Guo Qing Zhao ◽  
Jia Wang ◽  
Ming Gao

Objective.To investigates the effects of sufentanil post conditioning on Myocardial ischemia reperfusion injury in rats in vivo.Methods.To randomly divide 40 male SD rats equally into 4 groups, including Sham group, ischemia-reperfusion group (Group I/R ), ischemic post conditioning group (Group IPO) and sufentanil post conditioning group (Group SUF). The left anterior descending coronary arterys (LAD) of rats in 4 groups are ligated for 30 minutes and are re-perfused for 120 mins. To measure the myocardial infarction size (IS/AAR%) with double-staining with Even's blue and triphenyltetrazolium chloride, to calculate the concentration of cTnI, and to observe the HE staining and the expression of Bcl-2 and Bax.Result. Comparing with Group 1/R, the myocardial infarction size (IS/AAR%), and the concentration of cTnI in Group IPO and SUF all reduced significantly. Comparing with Group 1/R, cell morphological observation shows less change in pathology. And the expression of Bcl-2 increases and expression of Bax decreases in Group IPO and SUF than that in Group 1/R.Conclusion. Sufentanil post conditioning has protective effects on myocardial ischemia-reperfusion injury in rats in vivo.


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